Thermal spark retard



June 3, 1969 B. WALKER THERMAL SPARK RETARD Original Filed Oct. 23, 1965 4 I .Ifll

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United States Patent U.S. Cl. 123-117 6 Claims ABSTRACT OF THE DISCLOSURE A device for retarding the spark of internal combustion engines by a thermostatic operated valve to vary the vacuum operated advance until the engine is warmed.

This is a continuation of application Ser. No. 503,035 filed Oct. 23, 1965, now abandoned.

This invention pertains to a device for retarding the spark of internal combustion engines for faster warm up, the retard to operate when the thermostat that operates the choke is holding the choke in a full or partial choke position.

Another feature is to vary the spark retard from cutting out the vacuum advance almost completely when the engine is cold enough for the thermostat to give a full choke to cutting out part of the vacuum advance at part choke.

Another feature is use of a tapered needle bleed valve in the circuit to the vacuum advance combined with a limited rate of flow of vacuum or suction from the intake manifold or carburetor tap to the diaphragm that controls the vacuum advance and the control of said needle bleed by the thermostat that operates the carburetor choke to reduce or eliminate the vacuum controlled spark advance when the thermostat is choking the cold engine and gradually returning the spark to full vacuum advance operation as the engine warms up and no choke is needed.

This retard, when the engine is cold, speeds up the warming up of the engine and reduces the unburned hydrocarbons during the warm up period.

The use of the thermostat that operates the carburetor choke to also operate the reduction or elimination of the vacuum advance effects an economy over using another heat sensor or thermostat for the spark control.

The advantages to this spark retard when the engine is cold is a faster warm up, reduced unburned hydrocar bons, reduced time the choke is needed, saving of fuel, less crankcase dilution due to reduced choking and reduced warm up time, faster warm up of car heater, etc.

Other features will be pointed out in the accompanying specification and claims.

I have illustrated my invention in the accompanying drawings, in which:

The figure is a side view partly in section and partly diagrammatic showing one form of the invention.

In all figures like numerals of reference refer to corresponding parts.

Carburetor 20 has port 21 which is connected to line 22 which leads to suction operated spark advance or retard device 30 through flow rate control valve 23, tube 24, tube 25, substantially as is used conventionally except for valve 23, all of which is described in Glenns Auto -Repair Manual, 1962 Edition, page 360 (a copy of which is included).

Bleed or selector valve 27 is connected between line 24 and line 25 by line 29. Bleed needle 27b is operated by the motion of choke control rod 28 by thermostat 13 in exhaust manifold 12 so that the orifice 27a is open when the choke 15 is closed and gradually closed as the choke 15 is opened.

Valve 27 when open renders the suction controlled side of spark advance mechanism 30 (the upper side of diaphragm 31), as viewed in the figure inoperative and therefore retards the spark compared to normal while the engine is warming up for quicker warm up, less unburned hydrocarbons in the exhaust, and quicker car heater warm up. An idle engine retard may be used by passing the suction of intake manifold 10 through line 35 to valve 36 which is closed when the suction is above the idle suction to shut off or bleed the suction to the lower side of diaphragm 31 of device 30 when decelerating above a predetermined setting. From valve 36 suction passes through valve 38 which is opened when the throttle is closed or after the throttle is closed, as shown in my co-pending patent application Ser. No. 492,498 entitled Engine Spark Control.

From valve 38 suction flows through line 39 to the under side of diaphragm 31 to give a retard to breaker plate 40 (which supports breaker arm 41 in the conventional manner) when high engine suction is applied to the under side of diaphragm 31. This high suction and the retard by device 30 is effective when the engine is idling at closer or idle throttle setting but not when decelerating at higher engine speeds if valve 36 is used. If it is desirable to have the retard during decelerations to reduce brake fight or reduce unburned hydrocarbons or for other reasons, valve 36 may be left out and valve 38 only may control, in which case suction on the lower side of diaphragm 31 and retard of breaker plate 40 will result whenever valve 38 is open as when the throttle is closed or the control mechanism moves beyond the throttle closed position, all as described in my co-pending patent application Ser. No. 492,498, entitled Engine Spark Contro Breaker plate 40 is mounted in distributor mechanism 42 in the conventional manner. Cam 43 may be driven by a governor advance mechanism (not shown) in a conventional manner.

I have illustrated my invention in these various forms; however, many other variations may be possible within the scope of this invention.

To those skilled in the art to which this invention relates many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and description herein are purely illustrative and are not intended to be in any sense limiting.

I claim:

1. An internal combustion engine comprising at least one cylinder, an intake manifold and an exhaust manifold connected to said cylinder, and a carburetor for supplying fuel to said cylinder through said intake manifold, means for spark igniting the fuel in each cylinder, and means for varying the timing of the spark, said timing means comprising a suction operated motor, conduit means for connecting said motor to a suction source and atmosphere, and heat responsive means for gradually selectively connecting said conduit means to said suction source or atmosphere in accordance with the temperature of a component of said engine, said heat responsive means comprising a thermostat in the exhaust manifold and a valve connected without lost motion to the thermostat.

2. A device as defined in claim 1 wherein said heat responsive means comprises a temperature sensing motor and a valve connected thereto for producing operation of said suction operated motor to provide less suction operated spark advance with a cold motor than with a fully warmed up motor.

3. A device as defined in claim 1 wherein the compo nent is the exhaust manifold.

4. An internal combustion engine comprising at least one cylinder, an intake manifold and an exhaust manifold connected to said cylinder, and a carburetor for supplying fuel to said cylinder through said intake manifold, means for spark igniting the fuel in each cylinder, and means for varying the timing of the spark, said timing means comprising a suction source and atmosphere, and heat responsive means for gradually selectively connecting said conduit means to said suction source or atmosphere in accordance with the temperature of a component of said engine, a choke valve, said heat responsive means comprising a thermostat and a selector valve connected thereto, and means connecting the choke valve and selector valve for concurrent movement by the thermostat whereby opening movement of the choke valve is concurrent with the closing movement of the selector valve.

5. A device as defined in claim 4 wherein said suction motor comprises a housing and a diaphragm therein dividing the housing into separate chambers, means connecting said conduit means to one of the chambers, a second conduit means connecting the other of said chambers to said manifold, and valve means'in said second conduit for closing said conduit at full throttle operation of the engine and opening said conduit at engine idle closed throttle.

6. A device as defined in claim 5 in which said second conduit is closed at closed throttle decelerations above a predetermined engine speed.

' References Cited UNITED STATES PATENTS 2,136,353 11/1938 Weber "123 419 2,532,069 11/1950 Mallory 123 117 WENDELL E. BURNS, Primary Examiner.

US. Cl. X.R. 123--119 

